1. Field of the Invention
The present invention relates to a spindle motor for use in a disk drive apparatus, the disk drive apparatus, and a method of manufacturing a stator.
2. Description of the Related Art
Disk drive apparatuses, such as hard disk drives, typically have spindle motors (hereinafter referred to simply as “motors”) installed therein. In a disk drive apparatus disclosed in JP-A 2012-74114, a base portion extending radially around a central axis includes a plurality of through holes. A U-phase common wire, a V-phase common wire, and a W-phase common wire are drawn out from a U-phase coil, a V-phase coil, and a W-phase coil, respectively, of a motor. The common wire of each phase is individually passed through a separate one of the through holes to reach a lower side of the base portion, and is electrically connected to a circuit board. Each through hole is sealed with a sealant, whereby entry and exit of a gas through the through hole is prevented.
In order to improve airtightness of the disk drive apparatus, it is desirable that the number of through holes defined in the base portion should be small. In the disk drive apparatus described in JP-A 2012-74114, however, three through holes are required for the three common wires. Meanwhile, in the case where the three common wires are joined together to define a stranded wire and the stranded wire is passed through only one common through hole, minute gaps are inevitably defined between the wires in the stranded wire. It is difficult to fill each of these gaps with the sealant, and the airtightness of the disk drive apparatus is reduced. Moreover, in the case where the stranded wire is passed through the through hole, it is necessary to increase the diameter of the through hole. A disk drive apparatus in which a through hole having a large diameter is defined tends to be reduced in airtightness.